Low loop wire bonding

ABSTRACT

A multi-die package includes a first semiconductor die and a second semiconductor die each having an upper surface with a plurality of bond pads positioned thereon. The multi-die package also includes a plurality of bonding wires each coupling one of the bond pads on the upper surface of the first semiconductor die to a corresponding one of the bond pads on the upper surface of the second semiconductor die. A bonding wire of the plurality of bonding wires includes a first portion extending upward from one of the second plurality of bond pads substantially along a z-axis and curving outward substantially along x and y axes in a direction towards the first semiconductor die. The bonding wire also includes a second portion coupled to the first portion and extending from the first portion downward to one of the first plurality of bond pads on the upper surface of the first semiconductor die.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to Malaysian Patent Application No. PI2011004279, filed Sep. 9, 2011, the disclosure of which is incorporatedherein by reference in its entirety for all purposes.

BACKGROUND

The present invention relates in general to semiconductor packaging and,more particularly, to wire bonding between contacts that are positionedat substantially the same height or level in a semiconductor package.

An aspect of semiconductor packaging involves a wire bonding process. Aconventional wire bonding process may use a conductive wire to connect asemiconductor die to a lead of a lead frame. This allows thesemiconductor die to electrically communicate with external systems. Thewire bonding process typically produces a loop in the conductive wire. Aheight of the loop determines a minimum allowable thickness of asemiconductor package.

Semiconductor packages are continually being designed to be morecompact. This can be accomplished by using multi die packages, reducingthickness of the packages, and/or minimizing size of the packages. Loopheight impacts each of these options.

Conventional methods of reducing loop height between contacts atdifferent levels may include pulling the bonding wire downward. Thisincreases stress in the bonding wire, however, and can lead tofracturing or cracking near ball bonds. Other methods include forming afolded loop in the bonding wire or forming a depression on a neckportion of the bonding wire. Quality of these methods is difficult toassess, however, and they generally reduce wire strength. One methodthat has been used with some success includes forming a first ball bondon a higher contact, then attaching a bonding wire to a lower contactusing a ball bond, and then attaching the bonding wire to the highercontact using a stitch bond.

For contacts at the same height or level, the loop height is typicallyreduced by pulling the bonding wire downward. As explained above, thisincreases stress in the bonding wire and can lead to fracturing orcracking near ball bonds. The stress can be reduced by separating thecontacts farther apart and lengthening the bonding wire. However, thisincreases lateral dimensions and size of the package. Other methods thathave been used to reduce loop height when connecting contacts atdifferent levels fail to provide the same benefit when used withcontacts positioned at the same height or level.

Thus, there is a need to reduce loop height in bonding wires used toconnect contacts that are positioned at the same height or level withoutincreasing wire length.

SUMMARY

Embodiments of the present invention provide short and low loop wirebonding between contacts positioned at substantially the same height ina semiconductor package. For example, in accordance with an embodimentof the present invention, a multi-die package includes a die pad and afirst semiconductor die positioned on the die pad. The firstsemiconductor die may include an upper surface having a first pluralityof bond pads thereon. The multi-die package also includes a secondsemiconductor die positioned on the die pad. The second semiconductordie may include an upper surface having a second plurality of bond padsthereon. The upper surface of the second semiconductor die may besubstantially coextensive with the upper surface of the firstsemiconductor die and extend substantially along a plane. The multi-diepackage also includes a plurality of bonding wires each coupling one ofthe first plurality of bond pads on the upper surface of the firstsemiconductor die to a corresponding one of the second plurality of bondpads on the upper surface of the second semiconductor die. A bondingwire of the plurality of bonding wires includes a first portionextending upward from one of the second plurality of bond padssubstantially along a z-axis and curving outward substantially along xand y axes in a direction towards the first semiconductor die. Thex-axis extends between the first semiconductor die and the secondsemiconductor die and the y-axis extends perpendicular to the x and zaxes. The first portion of the bonding wire may be located substantiallyabove the second semiconductor die. The bonding wire also includes asecond portion coupled to the first portion and extending from the firstportion downward to one of the first plurality of bond pads on the uppersurface of the first semiconductor die.

In an embodiment, the second portion extends substantially straight fromthe first portion downward to one of the first plurality of bond pads onthe upper surface of the first semiconductor die.

In another embodiment, the die pad comprises a first die pad and asecond die pad, the first die pad laterally spaced from the second diepad, the first semiconductor die positioned on the first die pad and thesecond semiconductor die positioned on the second die pad.

In yet another embodiment, a first end of the bonding wire is bonded toa first ball bond using a wedge bond, the first ball bond positioned onone of the first plurality of bond pads on the upper surface of thefirst semiconductor die. A second end of the bonding wire may be bondedto one of the second plurality of bond pads on the upper surface of thesecond semiconductor die using a second ball bond.

In accordance with another embodiment of the present invention, asemiconductor package includes a first bond pad on a first upper surfaceand a second bond pad on a second upper surface. The first upper surfacemay be laterally spaced from and substantially coextensive with thesecond upper surface. The semiconductor package also includes a bondingwire having a first end and a second end. The first end of the bondingwire may be coupled to the first bond pad, and the second end of thebonding wire may be coupled to the second bond pad. The bonding wireincludes a first portion extending upward from the second bond padsubstantially along a z-axis and curving outward away from the secondbond pad substantially along x and y axes in a direction towards thefirst bond pad. The x-axis extends between the first bond pad and thesecond bond pad and the y-axis extends perpendicular to the x and zaxes. The first portion may be located substantially above the secondupper surface. The bonding wire also includes a second portion coupledto the first portion and extending from the first portion downward tothe first bond pad.

In an embodiment, the second portion extends substantially straight fromthe first portion downward to the first bond pad.

In another embodiment, the first portion is coupled to the second bondpad using a ball bond.

In yet another embodiment, the second portion is coupled to a ball bondpositioned on the first bond pad using a wedge bond.

In accordance with yet another embodiment of the present invention, amethod of coupling a first end of a bonding wire to a first bond pad anda second end of the bonding wire to a second bond pad includes forming aball bond on the second bond pad using a portion of the bonding wire.The method also includes forming a first length of the bonding wire,where the first length is coupled to the ball bond and extends upwardfrom the ball bond substantially along a z-axis and curves outward awayfrom the ball bond substantially along x and y axes in a directiontowards the first bond pad. The x-axis extends between the first bondpad and the second bond pad and the y-axis extends perpendicular to thex and z axes. The first length may be located substantially above thesecond semiconductor die. The method also includes forming a secondlength of the bonding wire coupled to the first length, where the secondlength extends from the first length downward to a first ball bondpositioned on the first bond pad. The method also includes coupling thesecond length of the bonding wire to the first ball bond.

In an embodiment, the second length extends substantially straight fromthe first length downward to the first ball bond positioned on the firstbond pad.

In another embodiment, the method also includes, prior to forming theball bond on the second bond pad, forming the first ball bond on thefirst bond pad and tearing the bonding wire to separate the bonding wirefrom the first ball bond.

In accordance with yet another embodiment of the present invention, awire bonding method in which a wire passing through a capillary iscoupled to a first bond pad and to a second bond pad includes forming aball bond on the second bond pad. Thereafter, while paying out a firstlength of the wire, the capillary is raised vertically upwardsubstantially along a z-axis a first distance from the ball bond.Thereafter, the capillary is moved laterally substantially along a yaxis a second distance in a direction away from the ball bond. An x-axisextends between the first bond pad and the second bond pad and they-axis extends perpendicular to the x and z axes. Thereafter, thecapillary is raised vertically upward substantially along the z-axis athird distance.

Thereafter, the capillary is moved laterally substantially along the xaxis a fourth distance in a direction towards the first bond pad.Thereafter, the capillary is raised vertically upward substantiallyalong the z-axis a fifth distance. Thereafter, the capillary is movedlaterally substantially along the y-axis a sixth distance in a directiontowards the ball bond. Thereafter, the capillary is moved downward tothe first bond pad and the wire is coupled to the first bond pad.

In an embodiment, forming the ball bond comprises melting an end of thewire using an electric flame off to form a free air ball.

In another embodiment, prior to forming the ball bond on the second bondpad, a first ball bond is formed on the first bond pad and the wire istorn to separate the wire from the first ball bond on the first bondpad.

In yet another embodiment, coupling the wire to the first bond padcomprises forming a wedge bond on the first ball bond.

Numerous benefits are achieved using embodiments of the presentinvention over conventional techniques. For example, in one embodiment alow loop bonding wire having a J-shape when viewed from above can beformed between two contacts that are at substantially the same height orlevel. The bonding wire may have a loop height of no more than about 50μm above the contacts. This can reduce a minimum thickness of asemiconductor package. The J-shape can also reduce stress in the bondingwire. Depending on the embodiment, one or more of these benefits mayexist. These and other benefits are described more fully below.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a simplified plan view of a bonding wire having a J-shape inaccordance with an embodiment of the invention;

FIGS. 2A-2D are simplified side views of a bonding wire in accordancewith an embodiment of the invention;

FIGS. 3A-3B are simplified diagrams illustrating paths followed by acapillary during formation of a bonding wire in accordance with anembodiment of the invention;

FIG. 4 is a simplified diagram of a bonding wire in accordance with anembodiment of the invention;

FIGS. 5A-5J are simplified diagrams illustrating various positions of acapillary and various shapes of a wire during formation of a bondingwire in accordance with an embodiment of the invention;

FIG. 6 is a simplified diagram illustrating a path followed by acapillary during formation of a ball bond in accordance with anembodiment of the invention;

FIGS. 7A-7H are simplified diagrams illustrating various positions of acapillary during formation of a ball bond in accordance with anembodiment of the invention;

FIGS. 8A-8B are magnified images of an exemplary bonding wire inaccordance with an embodiment of the invention; and

FIG. 9 is a simplified flowchart illustrating an exemplary method ofcoupling a first end of a bonding wire to a first bond pad and a secondend of the bonding wire to a second bond pad in accordance with anembodiment of the invention.

DETAILED DESCRIPTION

Embodiments of the present invention provide wire bonding betweencontacts that are positioned at substantially the same height or levelin a semiconductor package. One or both of the contacts may be a bondpad on a semiconductor die, a bond pad on a substrate, a lead of aleadframe, or the like. In one embodiment, for example, the bonding wireconnects a bond pad on a first semiconductor die with a bond pad on asecond semiconductor die. The bonding wire may have a J-shape whenviewed from above. Such a bonding wire can provide a lower loop height,a shorter wire length, and/or a reduced stress compared to conventionalbonding wires.

FIG. 1 is a simplified plan view of a bonding wire having a J-shape inaccordance with an embodiment of the invention. The bonding wireelectrically connects two surfaces that are at substantially the sameheight or level. The surfaces in this example may be upper surfaces ofbond pads 106 a, 106 b and/or upper surfaces of semiconductor dies 108a, 108 b. The arrangement shown in FIG. 1 may exist in an assembledsemiconductor package that may also include an encapsulant material (notshown), or the arrangement may exist during a stage of assembly of asemiconductor package. Note that relative sizes and shapes of thefeatures, including the bond pads 106 a, 106 b and the semiconductordies 108 a, 108 b, are exaggerated for purposes of illustration.

As shown in FIG. 1, a bonding wire 102 extends between the bond pads 106a, 106 b. As will be explained more fully below, the bonding wire 102may be bonded to bond pad 106 a using ball stitch bonding, and thebonding wire 102 may be bonded to bond pad 106 b using ball stitch onball (or wedge) bonding. In this example, the bonding wire 102 has aJ-shape with a first portion that curves outward from the bond pad 106 ato a bend 110. The bonding wire 102 also has a second portion thatextends from the bend 110 the bond pad 106 b. As shown in this example,the first portion is located substantially above the bond pad 106 a, andthe second portion extends substantially straight from the bend 110 tothe bond pad 106 b.

The shape of the bonding wire 102 reduces loop height by forming thebend 110 and J-shape mostly along a horizontal plane that is parallelwith the upper surfaces of the bond pads 106 a, 106 b and/or the uppersurfaces of the semiconductor dies 108 a, 108 a. A maximum height of thebonding wire 102 above the bond pads 106 a, 106 b is near the bend 110.In an embodiment, the maximum height of the bonding wire 102 above theupper surfaces of the bond pads 106 a, 106 b and/or the upper surfacesof the semiconductor dies 108 a, 108 b is no more than about 50 μm. TheJ-shape of the bonding wire 102 also reduces stress by limiting thedownward pull at the bonds. The reduction in height and stress areachieved without increasing bonding wire length like conventionaltechniques.

The bonding wire 102 may comprise a number of conductive materials. Insome embodiments, for example, the bonding wire 102 includes at leastone of gold or copper. The bonding wire 102 may also be of any typicaldiameter. In some embodiments, for example, the bonding wire has adiameter of about 20 μm.

As would be appreciated by one of ordinary skill in the art, asemiconductor die may include a plurality of bond pads, and each bondpad may be electrically coupled to a corresponding bond pad of anothersemiconductor die or to a corresponding lead of a leadframe. Thus, atypically semiconductor package may include a plurality of bonding wiressimilar to the bonding wire 102 illustrated in FIG. 1.

FIGS. 2A-2D are simplified side views of the bonding wire 102 inaccordance with an embodiment of the invention. The view in FIG. 2A isfrom a perspective of point A shown in FIG. 1, and the view in FIG. 2Bis from a perspective of point B shown in FIG. 1. From theseperspectives, the bonding wire 102 extends between ball bonds 104 a, 104b and connects the semiconductor dies 108 a, 108 b. The bond pads 106 a,106 b are not visible in these figures. These figures show the firstportion of the bonding wire 102 extending from the ball bond 104 a tothe bend 110, and the second portion of the bonding wire extending fromthe bend 110 downward to the ball bond 104 b. A convex portion of thebend 110 is visible in FIG. 2A, and a concave portion of the bend 110 isvisible in FIG. 2B. As can be seen in these figures, one end of thebonding wire may be bonded using ball stitch bonding, and the other endof the bonding wire 102 may be bonded using ball stitch on ball (orwedge) bonding.

FIG. 2C is from a perspective of point C shown in FIG. 1, and FIG. 2D isfrom a perspective of point D shown in FIG. 1. In these figures theperspectives are from points slightly above the upper surface of thebond pads 106 a, 106 b. These figures show the bonding wire 102extending between the ball bonds 104 a, 104 b and connecting the bondpads 106 a, 106 b. The first portion of the bonding wire 102 extendsupward from the ball bond 104 a substantially along a z-axis and curvesoutward substantially along x and y axes in a direction toward thesemiconductor die 108 b. In this example the x-axis extends between thesemiconductor dies 108 a, 108 b, and the y-axis extends perpendicular tothe x and z axes. The second portion of the bonding wire extends fromthe bend 110 nearly straight to the ball bond 104 b.

FIGS. 3A-3B are simplified diagrams illustrating a path followed by acapillary during formation of a bonding wire in accordance with anembodiment of the invention. The path may be used to produce a bondingwire having a J-shape similar to that shown in FIG. 4. FIG. 3A shows thepath in three-dimensions and includes changes in X, Y, Z directions.FIG. 3B shows movement of the capillary along an X-Y plane when viewedfrom above (looking in a negative Z direction).

As shown in FIG. 4, the bonding wire 402 extends between ball bonds 404a, 404 b and electrically connects bond pads 406 a, 406 b ofsemiconductor dies 408 a, 408 b. In this example the semiconductor dies408 a, 408 b are positioned on respective die pads 410 a, 410 b. Notethat the bond pads 406 a, 406 b may not protrude above the uppersurfaces of the semiconductor dies 408 a, 408 b as illustrated in thisexample.

The bonding wire 402 includes a first portion that extends upward andoutward from the ball bond 404 a. The bonding wire 402 also includes asecond portion that extends downward from the first portion to the ballbond 404B.

FIGS. 5A-5J are simplified diagrams illustrating various positions of acapillary and various shapes of a wire during formation of a bondingwire in accordance with an embodiment of the invention. Each of thepoints A-H shown in the path illustrated in FIGS. 3A-3B are explainedwith reference to FIGS. 5A-5J. As shown in this example, the bondingwire is formed between contacts 506 a, 506 b. The contacts 506 a, 506 bmay be bond pads of semiconductor dies 508 a, 508 b disposed on die pads510 a, 510 b respectively. Upper surfaces of the contacts 506 a, 506 bare positioned at substantially the same height or level and are thussubstantially coextensive. Upper surfaces of the semiconductor dies 508a, 508 b are also positioned at substantially the same height or leveland are thus also substantially coextensive.

As shown in FIG. 5A, a ball bond 504 b may be formed on contact 506 b.Details of an exemplary method for forming the ball bond 504 b areprovided below with reference to FIGS. 6 and 7A-7H. FIG. 5A also shows awire 526 extending through a capillary 520. The capillary 520 may bepart of a larger bonding tool that is not shown for simplicity. A tailof the wire 526 that extends below the capillary 520 is heated andmelted using an electric spark 524 in accordance with known techniques.The electric spark 524 is generally referred to as an electric flame off(EFO) and may be generated using an EFO wand (not shown). The EFO meltsan end of the wire 526 to form a free air ball (FAB) 522.

In FIG. 5B, the capillary 520 is moved downward until the FAB 522 comesinto contact with contact 506 a. Ultrasonic energy and force may beapplied in accordance with known techniques to form ball bond 504 a onthe contact 506 a.

In FIG. 5C, a clamp opens and the capillary 520 is raised verticallyupward substantially along a z-axis a first distance from the ball bond504 a. The capillary 520 is raised from point A to point B while payingout a first length of the wire 526 (see FIG. 3A).

In FIG. 5D, the capillary 520 is moved laterally substantially along a yaxis a second distance in a direction away from the ball bond 504 a. Inthis example, an x-axis extends between the contacts 506 a, 506 b andthe y-axis extends perpendicular to the x and z axes. The capillary 520is moved from point B to point C (see FIGS. 3A-3B).

In FIG. 5E, the capillary 520 is raised vertically upward substantiallyalong the z-axis a third distance. The capillary 520 is moved from pointC to point D while paying out a second length of the wire 526 (see FIG.3A).

In FIG. 5F, the capillary 520 is moved laterally substantially along thex axis a fourth distance in a direction toward contact 506 b. Thecapillary is moved from point D to point E (see FIG. 3A-3B).

In FIG. 5G, the capillary 520 is raised vertically upward substantiallyalong the z-axis a fifth distance. The capillary 520 is moved from pointE to point F (see FIG. 3A).

In FIG. 5H, the capillary 520 is moved laterally substantially along they-axis a sixth distance in a direction towards the ball bond 504 a. Thecapillary 520 is moved from point F to point G (see FIGS. 3A-3B).

In FIG. 51, the capillary 520 is moved downward to a position near thebond pad 506 b. The capillary 520 is moved from point G to point H (seeFIG. 3A-3B). In an embodiment, the clamp within the capillary 520 closesbefore moving from point G to point H. At point H, the wire 526 may beconnected to the ball bond 504 b using ball stitch on ball (or wedge)bonding.

FIG. 5J shows the bonding wire formed by following the steps illustratedin FIGS. 5A-5J. Using these steps, the bonding wire may be formed tohave a maximum height (h) of no more than about 50 μm above an uppersurface of the contacts 506 a, 506 b (or a maximum h of no more thanabout 50 μm above an upper surface of the semiconductor dies 508 a, 508b if the contacts 506 a, 506 b and the semiconductor dies 508 a, 508 bare at approximately the same level). This compares to a loop height ofabout 150-200 μm using conventional processes.

FIG. 6 is a simplified diagram illustrating a path followed by acapillary during formation of a ball bond in accordance with anembodiment of the invention. The path may be used to produce a ball bondsimilar to the ball bond 504 b shown in FIG. 5A. FIGS. 7A-7H aresimplified diagrams illustrating various positions of a capillary duringformation of the ball bond in accordance with an embodiment of theinvention. Each of the points A₁-F₁ shown in the path illustrated inFIG. 6 are explained with reference to FIGS. 7A-7H.

FIG. 7A shows a wire 726 extending through a capillary 720. FIG. 7A alsoshows contacts 706 a, 706 b. The contacts 706 a, 706 b may be bond padsof semiconductor dies 708 a, 708 b disposed on die pads 710 a, 710 brespectively.

In FIG. 7B, a tail of the wire 726 extending below the capillary 720 isheated and melted using an EFO 724 in accordance with known techniques.The EFO 724 may be generated using EFO wand 728. The EFO melts an end ofthe wire 726 to form a free air ball 722.

In FIG. 7C, the capillary 720 is moved downward until the FAB 722 comesinto contact with the bond pad 706 b. Ultrasonic energy and force may beapplied in accordance with known techniques to form ball bond 704 b oncontact 706 b.

In FIG. 7D, a clamp opens and the capillary 720 is raised substantiallyvertically upward a first distance. The capillary 720 is raised frompoint A₁ to point B₁ (see FIG. 6). The first distance providessufficient clearance for subsequent movement of the capillary 720.

In FIG. 7E, the capillary 720 is moved laterally a second distance tooffset from the ball bond 704 b. The capillary 720 is moved from pointB₁ to point C₁ (see FIG. 6).

In FIG. 7F, the capillary 720 is moved downward a third distance. Thecapillary 720 is moved from point C₁ to point D₁ (see FIG. 6). A stitchor wedge-like bond is formed on top of the ball bond 704 b.

In FIG. 7G, the capillary 720 is moved laterally a fourth distance. Thecapillary 720 is moved from point D₁ to point E₁ (see FIG. 6). The wire726 at a neck of the ball bond 704 b may be weakened as the capillary720 moves from point B₁ to point C₁ and from point C₁ to point D₁.

In FIG. 7H, the capillary 720 is raised substantially vertically upwarda fifth distance. The capillary 720 is moved from point E₁ to point F₁(see FIG. 6). The clamp within the capillary 720 may close, and the wire726 may be torn from the ball bond 704 b leaving the ball bond 704 b onthe contact 706 b.

FIGS. 8A-8B are magnified images of an exemplary bonding wire inaccordance with an embodiment of the invention. The bonding wireillustrated in this figure may be formed using the steps illustrate inFIGS. 5A-5J and FIGS. 7A-7H. The view in FIG. 8A is from a perspectivesimilar to that of point A shown in FIG. 1, and the view in FIG. 8B isfrom a perspective similar to that of point B shown in FIG. 1. Fromthese perspectives, the bonding extends between ball bonds on each endand connects bond pads on each semiconductor die. These figures show afirst portion of the bonding wire extending upward from a ball bond andcurving outward to a bend (near right end of the bonding wire in FIG. 8Aand left end of the bonding wire in FIG. 8B). A convex portion of a bendis visible near a right end of the bonding wire in FIG. 8A, and aconcave portion of the bend is visible near a left end of the bondingwire in FIG. 8B. A second portion of the bonding wire extends from thebend downward to the other ball bond. In the embodiment shown, one endof the bonding wire is bonded using ball stitch bonding, and the otherend of the bonding wire is bonded using ball stitch on ball (or wedge)bonding.

FIG. 9 is a simplified flowchart illustrating an exemplary method ofcoupling a first end of a bonding wire to a first bond pad and a secondend of the bonding wire to a second bond pad in accordance with anembodiment of the invention. An upper surface of the first bond pad maybe substantially coextensive with an upper surface of the second bondpad. The method includes forming a ball bond on the second bond padusing a portion of the bonding wire (902). In an embodiment, a firstball bond is formed on the first bond pad prior to forming the ball bondon the second bond pad.

The method also includes forming a first length of the bonding wire,where the first length is coupled to the ball bond and extends upwardfrom the ball bond substantially along a z-axis and curves outward awayfrom the ball bond substantially along x and y axes in a directiontowards a first bond pad (904). In this example, the x-axis extendsbetween the first bond pad and the second bond pad and the y-axisextends perpendicular to the x and z axes. The first length may belocated substantially above a second semiconductor die. The method alsoincludes forming a second length of the bonding wire that is coupled tothe first length, where the second length extends from the first lengthdownward to a first ball bond positioned on the first bond pad (906).The method also includes coupling the second length of the bonding wireto the first ball bond (908). In an embodiment, the fourth length iscoupled to the first ball bond using ball stitch on ball (or wedge)bonding.

It should be appreciated that the specific steps illustrated in FIG. 9provide a particular method of coupling a first end of a bonding wire toa first bond pad and a second end of the bonding wire to a second bondpad in accordance with an embodiment of the present invention. The stepsoutlined above may be continuously repeated by system software. Othersequences of steps may also be performed according to alternativeembodiments. For example, the steps outlined above may be performed in adifferent order. Moreover, the individual steps illustrated in FIG. 9may include multiple sub-steps that may be performed in varioussequences as appropriate to the individual step. Furthermore, additionalsteps may be added or removed depending on the particular application.

It should be noted that some embodiments of the present invention may beimplemented by hardware, software, firmware, middleware, microcode,hardware description languages, or any combination thereof. Whenimplemented in software, firmware, middleware, or microcode, the programcode or code segments to perform the necessary tasks may be stored in acomputer-readable medium such as a storage medium. Processors may beadapted to perform the necessary tasks. The term “computer-readablemedium” includes, but is not limited to, portable or fixed storagedevices, optical storage devices, sim cards, other smart cards, andvarious other mediums capable of storing, containing, or carryinginstructions or data.

While the present invention has been described in terms of specificembodiments, it should be apparent to those skilled in the art that thescope of the present invention is not limited to the embodimentsdescribed herein. For example, features of one or more embodiments ofthe invention may be combined with one or more features of otherembodiments without departing from the scope of the invention. Thespecification and drawings are, accordingly, to be regarded in anillustrative rather than a restrictive sense. Thus, the scope of thepresent invention should be determined not with reference to the abovedescription but with reference to the appended claims along with theirfull scope of equivalents.

1-22. (canceled)
 23. A semiconductor package comprising: a first contact having an upper surface; a second contact having an upper surface, the upper surface of the first contact and the upper surface of the second contact being at substantially a same height and extending substantially along a plane; and a bonding wire coupling the first contact to the second contact, the bonding wire comprising: a first portion extending upward from the second contact substantially along a z-axis and curving outward substantially along x and y axes in a direction towards the first contact, the x-axis extending between the first contact and the second contact and the y-axis extending perpendicular to the x and z axes, and a second portion coupled to the first portion and extending from the first portion downward to the upper surface of the first contact.
 24. The semiconductor package of claim 23 wherein the first contact is at least one of a bond pad on a semiconductor die, a bond pad on a substrate, or a lead.
 25. The semiconductor package of claim 24 wherein the second contact is at least one of a bond pad on a semiconductor die, a bond pad on a substrate, or a lead.
 26. The semiconductor package of claim 23 wherein the first portion is located substantially above the second contact.
 27. The semiconductor package of claim 23 wherein the second portion extends substantially straight from the first portion downward to the upper surface of the first contact.
 28. The semiconductor package of claim 23 wherein a maximum height of the bonding wire above the plane is along the first portion and is no more than about 50 μm.
 29. The semiconductor package of claim 23 wherein a first end of the bonding wire is bonded to a first ball bond using a wedge bond, the first ball bond positioned on the upper surface of the first contact.
 30. The semiconductor package of claim 29 wherein a second end of the bonding wire is bonded to the upper surface of the second contact using a second ball bond.
 31. A method of coupling a first end of a bonding wire to a first contact and a second end of the bonding wire to a second contact, where an upper surface of the first contact and an upper surface of the second contact are at substantially a same height and extend substantially along a plane, the method comprising: forming a ball bond on the second contact using a portion of the bonding wire; forming a first length of the bonding wire, the first length coupled to the ball bond and extending upward from the ball bond substantially along a z-axis and curving outward away from the ball bond substantially along x and y axes in a direction towards the first contact, the x-axis extending between the first contact and the second contact and the y-axis extending perpendicular to the x and z axes; forming a second length of the bonding wire coupled to the first length, the second length extending from the first length downward to a first ball bond positioned on the first contact; and coupling the second length of the bonding wire to the first ball bond.
 32. The method of claim 31 wherein the first contact is at least one of a bond pad on a semiconductor die, a bond pad on a substrate, or a lead.
 33. The method of claim 32 wherein the second contact is at least one of a bond pad on a semiconductor die, a bond pad on a substrate, or a lead.
 34. The method of claim 31 wherein the first length is located substantially above the second contact.
 35. The method of claim 31 wherein the second portion extends substantially straight from the first portion downward to the first ball bond.
 36. The method of claim 31 wherein a maximum height of the bonding wire above the plane is along the first portion and is no more than about 50 μm.
 37. The method of claim 31 wherein the second length of the bonding wire is bonded to the first ball bond using a wedge bond.
 38. The method of claim 31 further comprising: prior to forming the ball bond on the second contact, forming the first ball bond on the first contact; and tearing the bonding wire to separate the bonding wire from the first ball bond.
 39. A wire bonding method in which a wire passing through a capillary is coupled between a first contact and to a second contact, the method comprising the steps of: forming a ball bond on the second contact; thereafter, while paying out a first length of the wire: raising the capillary vertically upward substantially along a z-axis a first distance from the ball bond; thereafter, moving the capillary laterally substantially along a y-axis a second distance in a direction away from the ball bond, an x-axis extending between the first contact and the second contact and the y-axis extending perpendicular to the x and z axes; thereafter, raising the capillary vertically upward substantially along the z-axis a third distance; thereafter, moving the capillary laterally substantially along the x-axis a fourth distance in a direction towards the first contact; thereafter, raising the capillary vertically upward substantially along the z-axis a fifth distance; thereafter, moving the capillary laterally substantially along the y-axis a sixth distance in a direction towards the ball bond; thereafter, moving the capillary downward to the first contact; and thereafter, coupling the wire to the first contact.
 40. The wire bonding method of claim 39 wherein the first contact is at least one of a bond pad on a semiconductor die, a bond pad on a substrate, or a lead.
 41. The wire bonding method of claim 40 wherein the second contact is at least one of a bond pad on a semiconductor die, a bond pad on a substrate, or a lead.
 42. The wire bonding method of claim 39 wherein coupling the wire to the first contact comprises forming a wedge bond on a first ball bond disposed on the first contact. 